howdy: VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV

Please describe the issue in as much detail as possible, including any errors and traces

The error is - VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV

howdy add - https://asciinema.org/a/ihNgoNb97s3wxTIPZWAnItt3D

$ sudo howdy add
Adding face model for the user anukul
Enter a label for this new model [Initial model]: 
VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV

Please look straight into the camera
Traceback (most recent call last):
  File "/usr/local/bin/howdy", line 90, in <module>
    import cli.add
  File "/lib/security/howdy/cli/add.py", line 117, in <module>
    enc = face_recognition.face_encodings(frame)
  File "/usr/local/lib/python3.6/dist-packages/face_recognition/api.py", line 199, in face_encodings
    raw_landmarks = _raw_face_landmarks(face_image, known_face_locations, model="small")
  File "/usr/local/lib/python3.6/dist-packages/face_recognition/api.py", line 153, in _raw_face_landmarks
    face_locations = _raw_face_locations(face_image)
  File "/usr/local/lib/python3.6/dist-packages/face_recognition/api.py", line 102, in _raw_face_locations
    return face_detector(img, number_of_times_to_upsample)
TypeError: __call__(): incompatible function arguments. The following argument types are supported:
    1. (self: dlib.fhog_object_detector, image: array, upsample_num_times: int=0) -> dlib.rectangles

Invoked with: <dlib.fhog_object_detector object at 0x7fd0819462d0>, None, 1

howdy test - https://asciinema.org/a/55hG9CnCcU6QQFfzEvHrkGQmz

$ sudo howdy test
VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV

Opening a window with a test feed

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Traceback (most recent call last):
  File "/usr/local/bin/howdy", line 102, in <module>
    import cli.test
  File "/lib/security/howdy/cli/test.py", line 85, in <module>
    overlay = frame.copy()
AttributeError: 'NoneType' object has no attribute 'copy'

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I’ve searched for similar issues already, and my issue has not been reported yet.

Linux distribution (if applicable): Ubuntu 18.04.1 on Dell XPS 9370

Howdy version: 2.4.0